ONSET CHARACTERISTICS OF LONG-TERM POTENTIATION IN THE GUINEA-PIG HIPPOCAMPAL CA1 REGION INVITRO
ONSET CHARACTERISTICS OF LONG-TERM POTENTIATION IN THE GUINEA-PIG HIPPOCAMPAL CA1 REGION INVITRO
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DOI：
10.1111/j.1460-9568.1989.tb00803.x
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发表时间：
1989-07-01
影响因子：
3.4
通讯作者：
WIGSTROM, H
中科院分区：
文献类型：
--
作者：
GUSTAFSSON, B;ASZTELY, F;WIGSTROM, H
在海马切片制备物的CA 1区域中检查了长时程增强（LTP）的时间发展（浴温30°C）。在印防己毒素存在下（以促进LTP诱导），通过单次短暂传入强直（50 Hz下3-40次脉冲）诱发LTP。通过比较印防己毒素溶液中获得的增强作用与正常溶液中获得的增强作用或在存在N-甲基-D-天冬氨酸受体拮抗剂2-氨基-5-膦酰基戊酸酯的情况下获得的增强作用，排除了与LTP无关的短暂增强作用过程。在印防己毒素溶液中，将单一测试齐射与短暂（2-3个脉冲）异突触强直配对也诱发LTP。这两种方法都没有显示出显着上升的LTP，直到约3秒后的诱导事件。LTP此后几乎呈线性发展，在破伤风后20-25秒内达到峰值，时间过程与诱导方法和诱发的LTP相对量无关。LTP的潜伏期和上升时间取决于浴温，25°C时约为30°C时的两倍。峰值后，LTP迅速衰减到不到一半的峰值在8分钟内，衰减趋势与较长的列车。LTP成分在强直后20-25 s达到峰值，在饱和同突触强直后几乎被闭塞，并且在1 h后仅部分恢复。LTP发作的潜伏期表明钙内流（推测触发增强作用）与LTP表达之间存在间接偶联。早期时间过程相对于感应强度的独立性表明介入系统以线性方式操作。
The temporal development of long‐term potentiation (LTP) was examined in the CA1 region of the hippocampal slice preparation (bath temperature 30°C). LTP was evoked by a single brief afferent tetanus (3–40 impulses at 50 Hz) given in the presence of picrotoxin (to facilitate LTP induction). Short‐lasting potentiation processes unrelated to LTP were excluded by comparing the potentiation obtained in picrotoxin solution with that obtained in normal solution or in the presence of the N‐methyl‐D‐aspartate receptor antagonist 2‐amino‐5‐phosphonovalerate. LTP was also evoked by pairing single test volleys with brief (2–3 impulses) heterosynaptic tetani in picrotoxin solution. Both methods showed no significant rise of LTP until about 3 s after the induction event. LTP thereafter developed almost linearly towards a peak within 20–25 s after the tetanus, the time course being practially independent of the induction method and of the relative amount of LTP evoked. The latency and rise time of LTP depended on bath temperature, being about twice as long at 25°C as at 30°C. Following the peak, LTP rapidly decayed to less than half its peak value in 8 min, the decay tending to be less with longer trains. The LTP component reaching its peak 20–25 s after a tetanus was practically occluded after a saturating homosynaptic tetanization, and was only partially recovered 1 h afterwards. The latency to the onset of LTP suggests an indirect coupling between the calcium influx, presumed to trigger the potentiation, and the expression of LTP. The independence of the early time course with respect to the induction strength indicates that the intervening system(s) operates in a linear manner.